total beginner

[codacola]

Hello everyone.
Ok, well I'm a complete beginner, and one question has been bugging me. if the f stop limits the amount of light, and so does the shutter speed, why not keep the f stop as low as possible and simply change the shutter speed?
thanks

 

[rogerbarry]

welcome

 

[Sideburns]

This is because different apertures, and different shutter speeds obtain different effects. Depth of field, and blur are both affected by those two things...and this can make a completely differnt photo depending on how you utilize them.

 

[Iron Flatline]

Hello everyone.
Ok, well I'm a complete beginner, and one question has been bugging me. if the f stop limits the amount of light, and so does the shutter speed, why not keep the f stop as low as possible and simply change the shutter speed?
thanks

Any good camera can do that, it's called Aperture Priority mode (a.k.a. Av Mode) whereby you select an Aperture (say f/2.8) and the camera automatically adjusts the shutter speed so you get a metered exposure. Or you can select Shutter Priority mode (Tv - Time value) and select a constant shutter speed. In that case the camera selects the appropriate Aperture to go with the fixed choice of shutter speed in order to get an exposure that the camera's meter suggests as appropriate. You're going to have to decide if the camera and its light meter is correct, or not giving you an exposure you like. In that case you dial in some Exposure Compensation, or just whack it into Manual mode and take full control.

 

[Buszaj]

aperture also lets you control DOF, so you can choose to blur the background with a shallow DOF (portraits are good for this), or deepen the DOF, (for landscape usually, I think). There are quite a few reasons for choosing a certain f stop and shutter speed.